Bidens pilosa L. - Asteraceae - Amor Seco (peruv.),Picao Preto (brazil.), Cadillo (venez., colomb.), Romerillo (cub.), hairy beggar-ticks, **Behaarter Zweizahn** Erect, branched annual herb, 0.30-1m high, native to tropical South America, cultivated and naturalized elsewhere; leaves ovate-lanceolate, opposite, 2-8cm long, serrate; small solitary flowerheads with tubular yellow florets. "The dried aerial parts of Bidens pilosa L. were extracted with petrol ether, chloroform, methanol, and methanol/water. The petrol ether and the methanol/water extracts showed some antimicrobial activity. Fractionation of the extracts yielded well known substances, most of which have, however, not yet been described as constituents of Bidens pilosa. Several of these substances have previously been shown to be biologically active. Thus, phenylheptatriyne, linolic acid and linolenic acid have antimicrobial activities. On the other hand, friedelin and friedelan-3β-ol, as well as several of the flavonoids found are anti-inflammatory agents. The detection of these compounds in extracts from B. pilosa may rationalize the use of this plant in traditional medicine in the treatment of wounds, against inflammations and against bacterial infections of the gastrointestinal tract." \\ [Constituents of //Bidens pilosa// L.: Do the components found so far explain the use of this plant in traditional medicine?, Geissberger, P., Séquin, U.R.S., Acta Tropica, Vol.48(4), 1991, 251-261] Decoction used externally to treat inflammation of the skin, internally against rheumatism and as diuretic. \\ [270 plantas medicinales iberoamericanas., Gupta, M.P. (Ed.)., Bogota, 1995] {{http://flora.huh.harvard.edu/FloraIllustration/foci20_21/foci20_21-689.jpg}} \\ [[http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200023537]]